Evan的app 學習筆記: android Keyguard 呼叫螢幕解鎖驗證

android 的 Keyguard 可以用來呼叫螢幕解鎖來驗證，

運用在有做自動登入時，避免使用者手機被偷，可以在app的重要功能再次要求解鎖

以下這個範例，

按下Verify按鈕時，會依照你的手機設定的解鎖方式開啟驗證(PIN、Password、Pattern、Fingerprint)

要使用Keyguard，API Level 21 以上。

先檢查手機是否有開啟螢幕鎖定。在Activity 叫起驗證頁，可以客制Title、Description

	private void showAuthenticationScreen() {
	if (keyguardManager.isKeyguardSecure()) {
	// Custom title description
	Intent intent = keyguardManager.createConfirmDeviceCredentialIntent("This is a custom title", "This is a custom description");
	if (intent != null) {
	startActivityForResult(intent, REQUEST_CODE_CONFIRM_DEVICE_CREDENTIALS);
	}else{
	this.result.setText("Secure lock screen hasn't set up");
	}
	}else{
	this.result.setText("Secure lock screen hasn't set up");
	}
	}

接收解鎖結果：

	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
	if (requestCode == REQUEST_CODE_CONFIRM_DEVICE_CREDENTIALS) {
	if (resultCode == RESULT_OK) {
	this.result.setText("Success");
	} else {
	this.result.setText("Cancel");
	}
	}
	}

完整程式：

	public class MainActivity extends AppCompatActivity {

	private static final int REQUEST_CODE_CONFIRM_DEVICE_CREDENTIALS = 1;
	private KeyguardManager keyguardManager;
	private TextView result;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_main);

	this.result = (TextView)findViewById(R.id.result);
	keyguardManager = (KeyguardManager) getSystemService(Context.KEYGUARD_SERVICE);
	}

	private void showAuthenticationScreen() {
	if (keyguardManager.isKeyguardSecure()) {
	// Custom title description
	Intent intent = keyguardManager.createConfirmDeviceCredentialIntent("This is a custom title", "This is a custom description");
	if (intent != null) {
	startActivityForResult(intent, REQUEST_CODE_CONFIRM_DEVICE_CREDENTIALS);
	}else{
	this.result.setText("Secure lock screen hasn't set up");
	}
	}else{
	this.result.setText("Secure lock screen hasn't set up");
	}
	}

	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
	if (requestCode == REQUEST_CODE_CONFIRM_DEVICE_CREDENTIALS) {
	if (resultCode == RESULT_OK) {
	this.result.setText("Success");
	} else {
	this.result.setText("Cancel");
	}
	}
	}

	public void verify(View view){
	this.showAuthenticationScreen();
	}
	}